1. Technical Field
The present invention relates to an image forming apparatus such as a copier, a printer, or a facsimile.
2. Background Art
As an image forming apparatus, there is known an image forming apparatus of a so-called electrophotographic type. In the image forming apparatus of the electrophotographic type, a toner image formed on a photosensitive body is transferred onto a sheet in an image transferring portion. A sheet on which an unfixed toner image is placed is removed from a photosensitive body to be conveyed on a sheet conveyor portion to downstream, and the toner image is fixed to the sheet in the image fixing portion. The sheet to which the toner image is fixed is further conveyed to be delivered to a delivery portion.
When a leading edge of the sheet onto which the toner image is transferred in the image transferring portion and which is removed from the image transferring portion is curled upwardly or downwardly, or floats from the sheet conveyor portion, the leading edge of the sheet cannot smoothly enter a nip portion between a fixing roller and a pressure roller which constitute an image fixing portion. Accordingly, at a position opposed to the sheet conveyor portion, there is provided a spur for regulating the sheet which is in a curled state or a floating state (see, Patent Document 1).
FIGS. 3A, 3B and 3B are views each showing a main structure of a related-art image forming apparatus.
As shown in FIG. 3A, the image forming apparatus includes a photosensitive drum 101 constituting the image transferring portion, and a fixing roller 104 and a pressure roller 105 constituting the image fixing portion. Between the photosensitive drum 101 and the image fixing portion, the sheet conveyor portion is formed by a conveying portion 102 for conveying the sheet and a guide plate 103 for guiding the sheet conveyed by the conveying portion 102 to an image fixing portion. Further, at a position opposed to the guide plate 103, there is provided a spur 112 for regulating the sheet which is in the curled state or the floating state. The spur 112 is rotatably supported by the support portion 111 fixed to a stay 110 of the image forming apparatus. A plurality of spur units each including the spur 112 and the support portion 111 for supporting the spur 112 are arranged in a width direction of the sheet.
[Patent Document 1] Japanese Patent Application Laid-open No. 2006-317626